The objective of this Phase I SBIR program is to demonstrate the efficacy of a new, 2.71 micrometer fiber laser in glaucoma surgery. This laser provides radiation in a region of the spectrum where water has very strong optical absorption. It is portable, reliable, and facilitates simple delivery because the laser consists of a flexible fiber. This laser offers the potential for sclerectomy with little or no conjunctival manipulation through the lack of a conjunctival incision with the ab interno techniques, or a small conjunctival incision with the ab externo techniques. The fiber laser offers access to surgically difficult areas for conventional surgery, and such laser procedures are often technically simpler than conventional surgery. The laser will be fabricated at Spire because lasers in this wavelength region are not commercially available. During Phase I, a breadboard laser will be fabricated and used in pre-clinical, in vitro procedures using human cadaver eyes at the New England Eye Center in Boston. Sclerectomy and laser trabecular ablation (LTA) procedures will be carried out with the fiber laser. Pulse widths and power levels will be bracketed from sclerectomy threshold to one log unit above threshold. Scleral tissue will be examined histologically for thermal damage zone extent. In Phase II a portable version of the laser will be designed and fabricated, and a comparison will be made between laser sclerectomy and conventional trabeculectomy, using rabbit models. Effects on outflow facility will be evaluated using LTA in cadaver human eyes. These procedures have been selected as ideal candidates for use with the 2.71 micrometer fiber laser. Successful completion of Phase II will enable Spire to manufacture a portable 2.71 micrometer fiber laser for use in a variety of medical applications. [unreadable] [unreadable]